Improvement in tubular steam-boilers



that@ /iatrt CHARLES A. THOMPSON,` OF FLSHING, NEW YORK.

Letters Patent No. 113,466, dated April 4, 1871.

IMPROVEMENT IN 'ruBuLAR STEAM-Bodens.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that LCHARLES A. THOMPSON, of Flushing, .in the county of Queens and Stateof N ew York, have invented au Improvement in Tubular Steam-Boilers, and the following is declared to be a correct description thereof.

yA tubular boiler has been made in which an iuclined water-shield has interposed between the ire and the ends of the horizontal filles, so as to compel the' products 'of combustion to travel around the said water-shield and heat the same; and also to protect the tube-sheet and tubes from the action of the in` tense fire. In boilers of this kind great dificulty has been experienced from an accumulation of ashes or einders upon the water-shield, closing the ends of the tubes in the lower ranges, and, at the same time, the upper tubes are injured byundue heat, and the heat is not full y abstracted from the products of conibustion in consequence of the insufciency iu the extent of heating-surface for the boiler.

An attempt has been made to prevent this banking of the 'ashes and oinclers by tubular openingsl through the inclined water-shield; but the sameforin lines that rapidly clog up or burn out, and thc heat doesnot all pass around the water-shield.

My invention consists in combining with the said tubular water-shield ranges of horizontal ilues, which tlues are of larger-diameter in the lower range or ranges than iu the upper. ranges of tubes, so that there will be a superior draught through the lower ranges of Atubes sutiicieut to carry through such tubes the ashes and cinders that would otherwise accumulate upon the' water-shield.

In the drawing- Figure 1 is a vertical section ol' the boiler longitudinally, and

lligure 2 is a cross-section at the line x The tire-box a, water-spaces l), boiler c, audescapef ne ll are substantially similar to those before coustrncted, with the exception that the tubes e e, that form the lowest range or ranges of tubes through the boiler, are of considerably larger diameter' than the tubes in ,the upper ranges,inorder that there may be a stronger draught through these lower tubes for conveying away the. ashes and cindersthat maybe carried up from the fire and lodge upon the upper surface of the water-shield y. l

This water-shield g acts to prevent ythe direct contact of the heat with the ends of the tubes, and said water-shield g may be at a greater or lesser inclination; a'ndwhere the tube-sheet is set bach from the line of the rear ofthe furnace the water-shield stands in a horizontal position, extending back to said tubesheet from the back edge of the furnace.

I claim as'my invention- 'Ihe boiler, Iliade with ranges of tubes ot' dilerent diameters, the lower range or ranges being ofthe largest diameter, in combination with the wateiwsliield,

for the purposes setforth.

Signed by me this 11th day of February, A. D. 187].

CHARLES A. THOMPSON.

Witnesses OHAs. E. SMITH, GEO. T. PINGKNEY. 

